Dermal patches for the transdermal administration of drug substances are known. One problem with these preparations is the resorption of sufficiently large amounts of active ingredient per unit area and per unit time, because many drug substances which are deposited on or stuck on to the skin in a topical preparation do not pass through the skin in sufficient amounts.
For this reason, so-called resorption accelerators, which are also termed penetration improvers, resorption promoters or enhancers, have been investigated and have been incorporated in dermal patches. In this manner, it has often been possible to achieve the desired pharmacological effect for the first time. Examples of resorption accelerators include propylene glycol, polyethylene glycols of lower molecular weight, oleic acid, isopropyl myristate, myristol, "Gattefosse" Transcutol, "Henkel" Eutanol, glycerol monolaurate (="Huls" Imvitor 312), a partial glyceride of ricinoleic acid (="Huls" Softigen 701), unsaturated polyglycolized glycerides (="Gattefosse" Labrafil M1944CS), "Gattefosse" Labrafac Hydro WL1219, Estasan GT60. saturated polyglycolized glycerides (="Gattefosse" Labrasol), phospholipids, etc. Further literature thereon: Rieg-Falson, F. et al. 1989, Watkinson, A. C. et al. 1991, and Hadgraft, J. and Guy. R. H. (eds.): Marcel Dekker Inc. N.Y. 1989.
A transdermal therapeutic system (TTS) having a backing film and having an acrylate-based pressure-sensitive adhesive, having a hormone content and a content of a plurality of resorption accelerators, is already known from WO-A-96/08 255, wherein
the hormone content is provided by a content of levonorgestrel, and
the resorption accelerators may comprise, amongst others, a C.sub.8-22 fatty acid such as oleic acid (page 6, line 25), or 2-(2-ethoxyethoxy)-ethanol, a mixture of oleic acid and 2-(2-ethoxyethoxy)-ethanol per se is not mentioned.
Acrylate-based pressure-sensitive adhesives form part of the prior art, such as those based on DUROTAK.TM., for example, which are obtainable by the radical polymerization of butyl acrylate, 2-ethylhexyl acrylate, methylacrylate, vinyl acetate, acrylic acid and/or hydroxyethyl acrylate; see the list of monomers for DUROTAK.TM.280-2287, for example.